The present invention relates to new 4-chlorooxazole derivatives, processes for their preparation and their use.
European Patent No. 0 010 652 discloses 4-chlorooxazole derivatives and the preparation and use thereof in photoconductive layers and as optical brighteners. The compounds are prepared by condensing an acyl cyanide with an aldehyde in the presence of hydrogen chloride. However, 4-chlorooxazole derivatives carrying unsaturated groups in the 2- or 5-position cannot be prepared according to this known method since, in the condensation reaction, there is also an addition of hydrogen chloride at the double bond.